August 13, 2014

I'm an Ebola Doctor Working in Liberia. Giving Every Patient That Rare Serum Doesn't Make Sense.

Brian Till's recent article in The New Republic, "Why Did Two U.S. Missionaries Get an Ebola Serum While Africans Are Left to Die?," raises an important point about inequality in access to healthcare. It would be bad enough if this inequality were limited to Ebola. But inhabitants of resource-limited countries like those in West Africa are denied many of the treatments that citizens of wealthier countries take for granted—despite being exposed to greater health risks, such as endemic malaria, poor quality drinking water, and emerging diseases like Ebola. This inequality is the source of much of the work that Médecins Sans Frontières—where I'm an Ebola specialist, currently working in Liberia—does every day.

Under ordinary circumstances, Ebola would be a neglected tropical disease—something for which no one is working on a treatment because the people who get it are too poor to be a valuable market for pharmaceutical companies. This changed when Ebola drew the interest of the defense community. It is a shame that Africa has to rely on this interest in the U.S. defense industry for the release of funding for research that has led to the development of Ebola treatments like the monoclonal antibodies that were used to save the two American missionaries.

Wouldn’t Africa be better off if there were an effective treatment for Ebola the continent could produce for itself? The solution proposed in Till's article, transfusion of convalescent serum, might seem a promising way to provide Africa with an independent means of coping with Ebola. However, the evidence supporting it is not very strong. For example, the study Till cites from the 1995 outbreak describes seven patients who survived when given serum from survivors. These seven survivors were given their plasma on an average of day eleven of their illness, which is rather late in the disease course. The average time to death in that outbreak was on day ten, so many patients receiving transfusions were more likely to survive even if they did not receive the serum. This does not prove that the patients received no benefit, but that they were not at the same risk of death as the average Ebola patient. This is known as selection bias. When coupled with the failure to show a benefit of convalescent serum in animal studies, the enthusiasm for pursuing this treatment option has waned.

But why not try? If the patients have a more than seventy percent chance of dying, why not try something, even if it is not guaranteed to work?

One reason is that doctors have a limited amount of time that we can spend with our patients. The protective clothing we wear in the Ebola treatment units is very good at keeping infectious fluids out, but equally good at keeping sweat in. Given that we're working in tropical temperatures, these outfits can be worn for less than an hour before overheating becomes a problem. And healthcare workers must use that brief window of time to provide all of the supportive and nursing care that their patients need. There is not a lot of extra time to experiment with unproven therapies.

And there are many such therapies. Dozens are brought to my attention with every outbreak. Some have shown promise in rodent models, others in test tubes, and some are of only theoretical benefit. Experience has shown that such potential almost always fails to produce a benefit in non-human primate studies, our best analog of human disease. We cannot subject our patients to all of the possible things that might work. We have to choose wisely.

The greatest hope lies with treatments that have shown efficacy in non-human primate studies. This brings us right back to where we began, with therapies like the ZMapp antibodies that were given to the two American missionaries, and similar therapies that have also shown promising results.

It is not because these drugs are expensive or intended just for North Americans and Europeans that they are unavailable to Africans. They are unavailable because they are not yet ready. For the antibodies used for the two Americans, only a handful of treatments exist in the world. None of these drugs has gone through the clinical trials needed for their approval for use by drug regulatory agencies. Médecins Sans Frontières hopes to play a role in facilitating the eventual trials that will bring these drugs to market, and from there to see to it that they are made available to the patients that need them.

Will this be expensive? Maybe. But we have been here before. Fifteen years ago, no one thought that antiretrovirals could be made available to Africans, but Médecins Sans Frontières was part of the fight to overcome the obstacles to treatment for people with HIV in Africa. Today these drugs are given to millions of people across the continent. These barriers can be overcome.

Ebola is already expensive, and we can barely take care of our patients now. When one of our healthcare workers in Liberia dons their protective gear, just for one hour with their patients, they have spent the equivalent of what the government spends on healthcare per citizen for the entire year.

It would be miserly of us not to go further to bring treatments that truly work to the people that need them. It is certainly encouraging to see the steps the WHO is taking to adopt exceptional regulatory procedures in the face of an exceptionally grave Ebola epidemic. It may not happen in time to help the victims of this outbreak, but it will happen, and it will change Ebola forever.

Dr. Armand Sprecher is a Public Health Specialist at Médecins Sans Frontières in Brussels.